mum Thành ngữ, tục ngữ
mum
say nothing of the secret you know Don
mum's the word
do not tell anyone, this is on the QT "She told us the secret. Then she whispered, ""Mum's the word."""
Keep mum
If you keep mum about something, you keep quiet and don't tell anyone.
Mummy's boy
A man who is still very dependent on his mother is a mummy's boy.
Mumbo Jumbo
Nonsense or meaningless speech.
mum is the word|mum|word
You must keep the secret; keep silent; don't tell anyone.

Often used as an interjection.
We are planning a surprise party for John and mum is the word. "Mum is the word!" the robber captain told his men.